The rare-earth element peak in r-process nucleosynthesis

Network calculations show that the peak near nuclear mass number ii approximate to 160 in the solar r-process abundance distribution forms not in the steady phase of the r-process, but only just Drier to freeze-out, as the free neutrons rapidly disappear. Its ultimate source is a maximum of nuclear deformation between the steady-phase r-process path and the valley of stability. Beta decay, neutron capture and photodisintegration combine to funnel nuclei into the A approximate to 160 region as the freeze-out nears and the r-process path crosses the deformation maximum on its way to stability.